Satellite-based multi-cell radio-communication satellite systems already exist, for example such as the THURAYA system.
An ETSI standard, designated “GEO-Mobile Radio Interface Specifications; Part 3: Network Specifications; Sub-part 2: Network architecture; GMR-1 03.002,” also defines the architecture of the satellite component of a multi-cell system for narrow bandwidth services in the context of the UMTS (Universal Mobile Telecommunication System).
Standards for new generation land-based systems called pre-fourth generation, or 3.9G, such as LTE (Long-Term Evolution 3GPP Technology) and WIMAX IEEE 802.16 (Worldwide Interoperability for Microwave Access), are in development and propose services with an even higher throughput. The deployment of such 3.9G fourth generation systems began in 2010.
Like third-generation systems, it is interesting to complete the fourth-generation land or terrestrial systems, which are profitable when the densities of user terminals are high, with satellite systems, which become profitable when one wishes to broaden the coverage of the land-based systems in areas with lower user terminal densities than those of the cells of a land system.
Due to the higher throughputs required by the services offered in a fourth generation system, there is a desire to decrease the size of the satellite cells so as to increase the capacity of the satellite system, i.e. the traffic volume that can be managed by the satellite system.
It is known to assign a frequency band to each satellite beam or in a corresponding manner to each satellite cell, following a given frequency reuse scheme.
Like the land case, in the case of narrowband services, it is also known to coordinate a set of transmitting and receiving stations, called “Gateway Transceiver Stations” (GTS), using a Gateway Station Controller (GSC).
These GTS transmitting and receiving stations only perform servile management of the physical layer, i.e. carrying out the implementation of transmissions from a stationary and/or dynamic configuration of the transmission resources allocated for each transmission channel for which the station is responsible and quality measurements by channel.
The configuration is determined by the Gateway Station Controller GSC, the domain of which is the management of the transmission resources of the GTS attached exclusively to it, or in other words, the management of the terminals attached to the cells associated with the GTS.
Such an architecture initially seems transposable to a fourth-generation satellite system.
However, due to the smaller cell size for a fourth-generation satellite system, and a stronger sensitivity to antenna misalignment of the satellite, the number of switches per unit of time of broadband traffic between adjacent cell coverages managed by two different access stations increases.
Flexible and effective management in terms of capacity of the broadband transmission resources that simultaneously guarantees service continuity in terms of absence of interruption and communications appears difficult to achieve with such a directly transposed architecture.